设计一种基于腔内全光纤模式复用器/解复用器(MUX/DEMUX)的少模环形光纤激光器,实现了LP01模、LP11模、LP21模及混合模式可切换的激光输出。实验结果表明,利用低串扰的全光纤模式MUX/DEMUX结合4×1光开关,激光器可在三个最低阶的线偏振(LP)模式及其混合模式之间进行切换,LP01模、LP11模、LP21模的泵浦阈值分别为40、60、80 mW,斜率效率分别为1.2%、0.82%、0.56%。对设计的少模环形光纤激光器结构进行数值模拟和参数优化,极大地改善了波长偏移问题,实现了小于0.032 nm的3 dB线宽。

提出了一种利用386EX嵌入式微处理芯片，以英创嵌入式网络模块为核心，基于GPRS通信网络的无线数据传输系统的整体解决方案。在分析GPRS和嵌入式网络模块特点的基础上，重点描述了数据传输系统的整体架构和软件设计流程。作为远程无线环境监测系统的数据传输子系统，该系统已经投入实际运行并取得良好效果。

Lidar is an efficient tool for remote monitoring, but the effective range is often limited by signal-to-noise ratio (SNR). The reason is that noises or fluctuations always strongly affect the measured results. So the weak signal detection is a basic and important problem in the lidar systems. Through the power spectral estimation, we find that digital filters are not suitable for processing lidar signal buried in noise. We present a new method of the lidar signal acquisition based on discrete wavelet transform for the improvement of SNR to increase the effective range of lidar measurements. Performance of the method is investigated by detecting the simulating and real signals in white noise. The results of Butterworth filter, which is a kind of finite impulse response filter, are also demonstrated for comparison. The experiment results show that the approach is superior to the traditional methods.

本文介绍了MPL型微脉冲激光雷达管理系统的设计.该系统具有动态获取激光雷达系统采集的大气时空数据信息,对数据进行分析,同时显示大气反演图、背景噪声图等功能.

本文首次提出耦合光纤环形腔干涉仪列阵,并给出其耦合波方程和矩阵理论以描述其输出特性。分别计算了由2～4只单模光纤方向耦合器构成的耦合光纤环形腔干涉仪列阵的输出特性。结果表明,适当地选择诸耦合器的参数,耦合光纤环形腔干涉仪列阵优于单个光纤环形腔干涉仪的带通特性和更宽的光谱范围。